Resistor element



Dec. 12, 1967 A. SCHAECHER RESISTOR ELEMENT 2 Sheets-Sheet 1 Origlnal Filed Sept. 6, 1963 e w W E E E w M f W w m W r1 p Z i l R 1W a Dec. 12, 1967 R. A. SCHAECHER RESISTOR ELEMENT 2, Sheets-Sheet 2 Origlnal Filed Sept. 6, 1963 INVEN TOR. ROlfl/D a 965417564715? BY MJM d 22% United States Patent 3,358,260 RESISTOR ELEMENT Roland A. Schaecher, Columbus, Nehru, assignor to Dale Electronics, Inc., Columbus, Nebn, a corporation of Nebraska Continuation of application Ser. No. 307,267, Sept. 6, 1963, now Patent No. 3,287,685, Nov. 22, 1966. This application May 18, 1966, Ser. No. 551,093

6 Claims. (Cl. 338-318) This application is a continuation of co-pending application Ser. No. 307,267, filed Sept. 6, 1963, now Patent Number 3,287,685.

Wire-wound and film-type resistors characteristically have a cylindrical core with the resistive element on the outer surface thereof. A metal cap is normally placed on the ends thereof to serve as a terminal connecting means.

A principal object of this invention is to provide a re sistor element which utilizes terminal blocks that will greatly enhance the heat dissipating characteristics of the resistor core without the use of terminal caps, and particularly will accelerate the heat dissipation from the core to the chassis upon which the resistor element is mounted.

A further object of this invention is to provide a resistor element of a material that serves to quickly dissipate heat from the middle of the resistor core without housing the entire unit in a heat dissipating jacket.

A still further object of this invention is to provide a resistor element wherein the terminal or mounting blocks thereof will facilitate the mounting of the resistor element to a chassis.

A still further object of this invention is to provide a resistor element which provides a terminal connecting means that will allow the resistance core to be rotated to any convenient angle within substantially 180 degrees of displacement. I

A still further object of this invention is to provide a resistor element which will permit the core element to be finely machined so as to prevent the creation of hot spots after the resistance material is placed thereon.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings, in which:

FIGURE 1 is a disassembled perspective schematic view of one form of the device of this invention;

FIGURE 2 is an elevational view of the assembled components of FIGURE 1 with a resistance element and a coating secured thereto;

FIGURE 3 is a sectional view of the structure in FIGURE 2 taken on line 3-3 of that figure;

FIGURE 4 is a schematic perspective view of the disassembled components of a second form of the device of this invention;

FIGURE 5 is an elevational view of the assembled components of FIGURE 4 with a resistance element and coating mounted thereon;

FIGURE 6 is a sectional view of the URE 5 taken on line 66 of that figure;

FIGURE 7 is a perspective view of a third form of the base core of this invention;

FIGURE 8 is an elevational view of the core of FIG- URE 7 with a resistance element and coating mounted thereon;

device of FIG- cylindrical core portion 34, which is .through in intersecting FIGURE 9 is a sectional view of the device in FIG- URE 8 taken on line 9-9 of that figure;

FIGURE 10 is a perspective view of the disassembled components of a fourth form of this invention;

FIGURE 11 is an elevational view of the assembled components of FIGURE 10 with a resistance element and coating material thereon; and

FIGURE 12 is a sectional view through the device of FIGURE 11 taken on line 12-12 of that figure.

With reference to FIGURE 7, the numeral 10 generally designates a resistor core base of integral construction and having an elongated cylindrical core portion 12 which has its ends terminating in rectangular terminal blocks 14 and 16. The material of the resistor core base 10 should have a high thermal conductivity such as that characteristic of beryllium oxide. A center bore 18 extends along the longitudinal axis of the resistor core base and intersecting bores 20 and 22 in the blocks 14 and 16 serve as mounting holes. Screws, rivets, or other connecting means serve to extend through the bore 20 or 22 to effect the connection of the resistor core base to a chassis means. As will be noted in both FIGURES 7 and 9, the diameter of the cylindrical core portion 12 is less than either the width or the height of the blocks 14 and 16.

Electro conducting band terminals 24 extend around the core portion 12 adjacent the ends thereof. These band termina.s are welded upon themselves at 26 and protruding terminal ends 28 extend radially outwardly therefrom. A resistance element 30 which can be either wire, film, or other comparable substance, is located on the surface of the cylindrical core portion 12 and is connected to each of the terminal bands 24. A high temperature silicone coating 32 covers the resistance element 30 but the blocks 14 and 16 are exposed to the atmosphere. The coating serves only to protect the resistance element from moisture and other environmental conditions. Terminal ends 28 are exposed to the atmosphere as they protrude through the coating 32.

With reference to FIGURES 4 through 6 an elongated similar in all respects to the elongated cylindrical core portion 12 of resistor core base 10, has an elongated center bore 36 extending along its longitudinal axis. Rectangular terminal blocks 38 and ,40 have pairs of bores 42 and 44 extending theredirections to serve as mounting holes in the same manner served by bores 20 and 22 in the terminal'blocks 14 and 16 of resistor core base 10. Recessed bores 46 extend inwardly into the inner face 48 of terminal blocks 38 and 40. Smaller apertures 50 extend through the terminal blocks 38 and 40 and are concentrically positioned with respect to the recessed bores 46. The diameter of the core portion 34 is less thanthe width or the height of the terminal blocks 38 and 40.

The ends of the cylindrical core portion 34 are adapted for reception within the recessed bores 46 of the terminal blocks, as shown in'FIGURE 5. Bolt 52 with head portion 54 and a threaded end 56 is inserted through the apertures 50 and recessed 'bores 46 of the terminal blocks and through the center bore 36 of the core portion 34. A nut 58 is afiixed to the threaded end 56 of the bolt 52 to effect the rigid connection of the terminal blocks to the core portion 34. Band terminals 24A, protruding terminal ends 28A,.resistance element 30A and coating 32A are applied to the cylindrical core portion 34 in precisely the same manner as the corresponding elements 24, 28, 30 and 32 were applied to the cylindrical core portion 12 of resistance core base 10.

A different means of mounting the elongated cylindrical core portion 34 is illustrated in FIGURES 10 through 12. There, a similar elongated cylindrical core portion 34A with a center bore 36A is supported by two mounting brackets 60. Each mounting bracket is comprised of a fiat apertured horizontal shoe portion 62 which has a vertical upstanding portion 64 secured thereto. The upstanding portions 64 terminate in a horizontal cylindrical portion 66. The cylindrical portion 66 of mounting brackets 60 are adapted for reception into the. center bore 36A of the cylindrical core portion 34A. As shown in FIGURE 11, the lengths of the horizontal cylindrical portions 66 of the two mounting brackets 60 are such that they will not touch when inserted into the center-bore 36A of the core portion 34A. The apertures inthe shoe portions of the mounting brackets are adapted to receive any convenient connecting means to secure the unit to a chassis support. Again, terminals 24A and terminal ends 28A, along with resistance element 30A and coating 32A, can be attached to the cylindrical core portion 34A in the same manner that they were attached to the cylindrical core portions 34'. The mounting brackets 60' are preferably of the same material as the core portions 34A, and again the material of the mounting brackets and the core should be similar to that of the resistor core base 10, as described above.

With reference to FIGURES 1, 2 and 3, a solid elongated cylindrical core 68 has indentations 70 in the ends thereof for receiving the head and tail stocks of a wire winding machine. Rectangular terminal blocks 72 and 74 have intersecting bores or mounting holes 76 and 78 therein to effect the securing of the unit to a supporting chassis in the same manner that bores 20 and 22 serve in core base 10. Recessed bores 80 appear in the inner faces 82 of terminal blocks 72 and 74 and are adapted to receive the ends of the cylindrical core 68. The securing of the terminal blocks to the chassis support serves to hold the core 68 within the recessed bores 80. Terminals 24B, terminal ends 28B, resistance element 30B and coating 32B serve the same corresponding functions as elements 24, 28, 30 and 32 serve in regard to core base 10, as described above.

All of the cores and terminal blocks described are of the same or comparable high-thermal conductivity as core base 10. Thus, the terminal blocks of these units aid rather than inhibit the dissipation of heat from the core units, and the blocks especially assist in conducting heat from the cores to the supporting chassis. The chassis structures have been designated by the numerals 84 in FIG- URES 3, 6, 9, l1 and 12. The hollow construction of the core base permits heat to be dissipated therefrom on,

both its inner and outer surfaces.

The mounting or terminal blocks described serve as an eifective means of securing the various units to these chassis structures. The core units and terminal blocks of the units in FIGURES 4, 7 and 10 are particularly adaptable for large resistor units, and the device of FIG- URE 1 is. well suited for smaller designs. The transverse mounting holes in the terminal blocks allow some flexibility in the direction that the terminal ends 28, 28A and 283 will extend, and the rotatable characteristics of cores 34A and 34B further assist this phenomenon. Because of the use of berylliumoxide as the material for the core units, the need for a heat dissipating shell or casing around the unit has been eliminated.

It is therefore seen that this invention will at least accomplish all of'its stated objectives.

Some changes may be made in the construction and arrangement of my resistor element without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use. of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In combination,

an elongated electrical resistance means including an.

elongated core with a resistance element thereon,

4 v V a bore portion in the ends of said core,

spaced apart mounting brackets adapted to be secured to a chassis means, and portions on said brackets rotatably and detachably extending into the bore portions of said core to support said resistance means; they material of said core and said mounting brackets being the same, said material comprised substantially of beryllium oxide to give said core and said mounting brackets characteristics of high thermal conductivity. 2. In combination, an elongated electrical resistance means including an elongated core with a resistance element thereon, said elongated core being of electrically insulative material, an elongated cylindrical bore portion in the ends of said core; spaced apart mounting brackets adapted to be secured to a chasis means, cylindrical portions of solid uniform construction on said brackets and detachably rotatably journaled within and extending into the bores of said core to support said resistance means; said cylindrical portions being complementary in shape to said bores to enhance the transfer of heat from said bore to said mounting brackets, and to facilitate the rotation of said core on said mounting brackets. 3. The combination of claim 2 wherein said cylindrical portions of said brackets are of solid construction throughout their cross-sectional area.

4. In combination, an elongated electrical resistance means including an elongated core with a resistance element thereon, said elongated core being of electrically insulative material, a bore portion in the ends of said core, spaced apart mounting brackets adapted to be secured to a chassis means, and portions on said brackets rotatably and detachably extending into the bore portions of said core to support said resistance means, each mounting bracket being comprised of a flat apertured horizontal shoe portion which terminates in a vertical upstanding portion, said upstanding portion terminating in a horizontal portion which extends into, a bore. portion at one end of said core. 5. In combination, an elongated electrical resistance, means including an elongated core with a resistance element thereon,

said. elongated core being of electrically insulative material, a bore portion in the ends of said core, spaced apart mounting brackets adapted to be secured to a chassis means, and portions on said brackets rotatably and detachably extending into the bore portions of said core to support said resistance means, the material of said core and said mounting brackets being the same. 6. In combination, an elongated electrical resistance means including an elongated core with a resistance element thereon, said elongated core being of electrically insulative material, a bore portion in, the ends of said core, spaced apart mounting brackets adapted to be secured to a chassis means, and portions on said brackets rotatably and detachably extending intothe bore. portions of said core to support said resistance means, said portions of said mounting brackets in said bore portions being elongated cylindrical elements.

(References on following page),

References Cited UNITED STATES PATENTS Heath 338-322 X Hallock 338-318 X Siegel 338-318 X Calvert 338-318 X Ziegler 338-302 Richter 338-302 Patterson 248-201 6 3,068,441 12/1962 Levy 338-317 3,102,249 8/1963 Schultz et a] 338-316 3,248,679 4/1966 Ganci 338-264 FOREIGN PATENTS 120,775 12/ 1945 Australia.

RICHARD M. WOOD, Primary Examiner. V. Y. MAYEWSKY, Assistant Examiner. 

5. IN COMBINATION, AN ELONGATED ELECTRICAL RESISTANCE MEANS INCLUDING AN ELONGATED CORE WITH A RESISTANCE ELEMENT THEREON, SAID ELONGATED CORE BEING OF ELECTRICALLY INSULATIVE MATERIAL, A BORE PORTION IN THE ENDS OF SAID CORE, SPACED APART MOUNTING BRACKETS ADAPTED TO BE SECURED TO A CHASSIS MEANS, AND PORTIONS ON SAID BRACKETS ROTATABLY AND DETACHABLY EXTENDING INTO THE BORE PORTIONS OF SAID CORE TO SUPPORT SAID RESISTANCE MEANS, THE MATERIAL OF SAID CORE AND SAID MOUNTING BRACKETS BEING THE SAME. 